The archaeology of Australia's tropical rainforests

Aboriginal exploitation of toxic nuts as a late-Holocene subsistence strategy in Australia’s tropical rainforests

“…One excavated Lauraceae endocarp fragment, a yellow walnut (Beilschmiedia bancroftii) or a black walnut (Endiandra palmerstonii), was submitted for 14 C analysis. The fragment returned a date of 1585 ± 40 BP (uncalibrated age; OZJ718) and is consistent with evidence for toxic plant use from other archaeological sites in the region (Horsfall 1987:268;Cosgrove et al 2007). The dated Lauraceae fragment from Urumbal Pocket provides a minimum age for the appearance of toxic nut processing in the rainforest.…”

“…However, it is possible there was some Aboriginal occupation on the edge of the rainforest ca. 30,000 years ago (Cosgrove et al 2007) and further work may reveal late-Pleistocene human occupation in the core rainforest area, as has been detected to the north of the study area (Haberle and David 2004;Summerhayes et al 2010).…”

“…The earliest dates at Urumbal Pocket, 7445 ± 68 BP (8273 ± 67 cal BP [Wk-13578]) and 7212 ± 46 BP (8052 ± 65 cal BP [Wk-13571]) are from charcoal found in the lower spits of Unit 2 together with a small number of quartz artefacts. The dates coincide with an initial period of Holocene rainforest expansion, and correspond with increases in microscopic charcoal in the pollen record (Haberle 2005;Cosgrove et al 2007). A further six AMS dates (bold in Table 1) were obtained from in situ diagnostic endocarp fragments.…”

“…These include social intensification (Lourandos 1997:303, 305) and broad-spectrum resource use (Haberle and David 2004), population increase and ceremonial activities (Beaton 1983(Beaton , 1985(Beaton , 1990), large-scale climatic change (Morwood and Hobbs 1995:182) and highintensity El Niño Southern Oscillation (ENSO) activity (Rowland 1999;Cosgrove 2005;Turney and Hobbs 2006;Cosgrove et al 2007). Unravelling the causes for an increase in the use of poisonous food plants is dependent on a capacity to build solid regional frameworks of archaeological and palaeoecological data that include an understanding of (i) substantial archaeological evidence of ancient plant remains, (ii) site formation and taphonomic processes, (iii) an identification of associated changes in other cultural remains with matching palaeoenvironmental signals, and (iv) commensurate regional site comparisons that have stratigraphically intact dated deposits.…”

“…Wide-ranging archaeological research in the Atherton-Evelyn Tableland region of north Queensland (Horsfall 1987(Horsfall , 1996Cosgrove and Raymont 2002;Cosgrove 2005;Cosgrove et al 2007;Ferrier 2010) has shown that the majority of the archaeological material dates to within the past 5000 years, with human occupation initially at very low levels, while it was only within the past 2000 years that occupation intensified. Here, we expand on the current understanding of what appears to be a late-Holocene intensification in site occupation and Aboriginal use of toxic food plants in north Queensland's Wet Tropics Bioregion, with an analysis of the macro-botanical remains excavated from Urumbal Pocket, an open archaeological site on the Evelyn Tableland (Figure 1).…”